The problem is that large swathes of the Git community have been treating the whole DVCS scene almost in Hunger Games terms -- there can be only one winner, and all the others must die.
For what it's worth, I've heard quite a lot of anecdotal evidence that Git is pretty contentious among many teams that adopt it. Git adoption is often driven by an aggressive few, against the wishes of their colleagues who can be quite unhappy about it. Case in point: Git has more "hates" on amplicate.com than Subversion and TFS put together -- and "hates" outnumber "loves" by something in the region of four to one. (http://amplicate.com/hate/git)
(For reference, Git and TFS have roughly similar market share in the enterprise at the moment, and Subversion is about twice as widely used as either of them. Source: itjobswatch.co.uk)